5 to 10 times speedup in common compilations with ccache

newcfd

http://ccache.samba.org/
ccache is a compiler cache. It acts as a caching pre-processor to C/C++ compilers, using the -E compiler switch and a hash to detect when a compilation can be satisfied from cache. This often results in a 5 to 10 times speedup in common compilations.
how to use it. Add ccache to Makefile
CC       = ccache gcc
CXX      = ccache g++
in makefile
If you have multi-core CPU, compile with
    make -j 4 (if you 2 cores)
    make -j 6 (if you have 4 cores)
It can speed-up a lot